Automatic control of centrifugal devices



Feb. 21, '1939. Q A. QLCOTT 2,148,320

AUTOMATIC CONTROL OF CENTRIFUGAL DEVICES Filed April 2, 195e lNvr-:NTOR CHARLES A. OLCOTT BY His ATTORNEYS Patented Feb. 21, A1939 uNITEDfsTATEs PATENT oFFlcr: Amomrrc conir cEN'rmUGAL charles A. mwa, Manteau, N. J. Application April 2, 1936, Serial No'. 72,390

8 Claims.

This invention relates yto control means for centrifugal machines such' asare used in drying and washing sugar and similar solids and it is an object ofthe invention to provide means for automatically controlling operations of such machines. It is a further object of this invention to provide such a-Jmeans that its operation will be started upon completion of the loading of the basket of the centrifugal machine with material lo to be treated.

In the drawing- ,.Flg. 1 is a diagrammatic view illustratinga preferred form of this invention; and.

Fig. 2 is a view in elevation of the operating l5 parts of a timing mechanism used.

' In the drawing there is shown ya perforated basket i of a centrifugal machine driven through shaft Thy-9, motor 3 havinga 'rotor '4. 'I'he motor is usually a multi-phase alternating current motor but for the sake of clearness there is shown in the drawing but one phase 'oi the usual power circuit. The stator of the motor is provided with a high speed winding 6 and a low speed winding 8 in order that the motor may operate the basket at diierent speeds. Fixed on the Vshaft 2 is a brakedrum I0 arranged to be engaged by a brake shoe I2 and positioned above the basket i is the loading spout i4, the discharge from which is controlled by a gate I6 operated by a lever or handle i6.

Current for the low speed operation of the motor 4 is supplied from the lead L1 of the line through leads 20 and 22 to 'the contacts of a,4 switch PB2, when the switch is operated against A the action of a spring, lead 23 to the low speed winding 8, leads 24 and 25 to switch SW-I and leads 26, 21 and 28 tov the lead L2 of the line.

The switch PB-2 is spring-operated to a position in which the contacts of.'leads` 22 and 23 are normally disconnected and `contacts oi leads 22a and 23,a are' normally connected. Switch PB-2 in its normal position, that is, when not :operated manually, establishes communication through the leads 20, 22, 22, 23 to the lead 29 so that when the switchjjPB-l is closed current from the line will pass from lead 29 through lead 30 and the contacts ofthe switch PB-i to the lead 32 and lead 34 where it divides, part of the current passing through the high speed winding 6 to lead 25 while a part passes through the `solenoid 36 of the switch PB-I and through lead 3B to the lead 25` through which it passes with rthewcurrjent from the high speed winding 6to the switch SW--i and through the leads 26, 21 and 28to-the lead U' of the line. The solenoid 36 isprovided so that when the switch PB-I is closed manually against the action of the spring the solenoid is energized and retains the switch closed until the circuit through the high speed 4winding 6 is opened.

The switch SW-I is shown as connected to a piston 40 in ,a cylinder 4I which is operated by air supplied through a valve 42 operated by a solenoid 43, the air being supplied through pipe 44 from suitable source of air pressure and pass- 1c ing through pipe .46 not only to the cylinder 4i but to a cylinder 48 in which is operated the piston 50 which applies the brake shoe I2 to the brake drum Il) so that upon admission of air pressure to the pipe 46 the brake is applied and l5 the switch SW-I opened to `cut oli the power to the machine. `The valve 42 is a three-Way valve which, in its normal position, is opened so as to vent pressure from the cylinders All' and dit to the atmosphere but which closes the vent when 2@ the valve is operated to supply pressure to the Y cylinders.

Energization of the solenoid Qt is controlled by a timing device T--i which comprises a selfstarting synchronous motor 52 such as is used 25 in electric clocks, a' solenoid'Sfl, which'controls the connection between the motor 52 and the movable arm which closes the contacts 56. To control the energization of the motor 62 and solenoid 54 there is provided an extension iiiEL on the lever 30 I8 which operates the gate I6 of the iilling spout and which extension la is provided at its outer end with an adjustable set screw 56 adapted, when the lever I6 is in its lowermost position, to eifect the closure oi switch SVV-2. The switch is 35 `spring-biased to open position, sothat while the lilling spout is opened the switch SVV-2 is opened but upon closure of the filling spout by the gate I6 upon completion of the filling of the basket the switch SW-2 is closed completing a circuit 40 from the lead L1 through leads 2 6, 22, 22, switch PB-2, leads 23'L and 26 to switch SW-2, lead 60 to the terminals b and c oi the timing means T-i. From the terminal c the circuit extends through the limit switch 62 and motor 62 to the 45' terminal a and thence through leads 21 and 28 to the lead L2 o1I the line while from terminal b the current passes through the solenoid 54 to terminal a and thence through the leads 21 and 28 to the lead l.,a causing the operation of the 50 motor 52 and energization of the solenoid 54. The timing device 'iF-l is arranged so that at a predetermined time after the closure of the switch SVV-2, starting` the motor 52 and energization of the solenoid 54, the contacts 56 wil1 ,b, e closed 55 completing a circuit from the lead L1 through leads 20, 22, 22a, 23, 29 to terminal d, through contacts 56 to the terminal e and thence through the lead 64, solenoid 43 and leads 21 and 28 vto the lead L2 of the line, energizing the solenoid 43.

the connection of the motor with the means for y operating the contacts 56a and 56". The timing means T-2 is also controlled by the switch .SW-2 operated by the handle I8 and upon closure of the switch SW-2 current is supplied from the lead 60 through lead 14 t0 the terminals b1, cl and d1. From the terminal c1 the current passes through the limit switch 62a and motor 52 to the terminal all and thence through leads 16 to lead 28 and the lead L2 ofthe line. Current also passes from the terminal b1 through the solenoid 54HL to the terminal a1 and thence through leads 16 -to the lead L2. As was the case with the timing means T-I, operation of the motor 52 causes the operation of the contacts 56a and 56b after predetermined times. Contacts 56a are normally open while contacts 56b are normally closed so that upon closing of the contacts 56a the circuit is completed from the 'lead 14 ,to terminal d1, thence through the contacts 563 `and 56b to terminal e1, lead 18 and solenoid 12 to lead 16 and the lead Il2 energizing the solenoid 12 and operating the valve 68 to supply the washing liquid to the spray-head 10.

After closing thecontacts 56- the motor continues its operation until contacts 56b are opened.

Thus, after being closed a predetermined time the circuit is opened at the contacts 56h and the solenoid 12 is de-energized, cutting off the supply of wash liquid to the basket and thereby providing the wash liquid for a predetermined period de pending upon the positioning of the contacts 56a and 56". In both the timing devices the limit switch 62 serves to stop Athe operation of the motor after a predetermined time beyond that which is necessary for the operation of the contacts 56, 56 and 56h.

A suitable structure of the timing devices for u seiin this invention is shown in Figure 2, in which means for operating the contacts 56a and 56b are shown. In this structure the motor 52, through worm 80, drives a gear 82 fixed on a shaft 84. Loosely mounted onthexshaft 94 is an arm 86 having an extension thereon in which is pivoted the dog or pawl 88 arranged to be operated by solenoid 54, when solenoid 54 is energized, to engage the pawl with the teeth of the' gear wheel 82 so that the arm 86 will be moved with the gear wheel.

Loosely mounted on the shaft is an arm 90 on which are the contacts 56 and a second arm. 92 on which are mounted the contacts 56h. The arms 90 and 92 may b`e positioned at diierent distances with respect to the arm 86 so as to vary the'time taken by the arm 86 to approach and operate the contacts on the arms, arm 92 beingv adjusted manually by extension 92EL while arm 90 is adjusted manually by the arm e, the ends of the arms n and 92 serving as pointers'ona graduated scale to indicate the time required for the operating arm 86 to approach and operate the contacts.- To operate the contacts the arm- 86 is provided with a pin 88a adapted to engage the contacts 56B and close these contacts after a predetermined period of operation depending upon the distance of the contacts from the arm 86 when in normal position. The arm 90 is thereupon moved with the arm 86, and projection 90b of the arm 90 after a predetermined period engages with the extension of one of the contacts 56b and separates these contacts thereby opening the circuit which was closed when the contacts 56a were brought together. While the showing of Figure 2 is applicable to the two contacts shown in timing means T-2 it will be appreciated that the timing means T-I comprises only one set of contacts 56 which correspond to the contacts 56 of the timing means T-2. Upon de-energization of thev Where desired a switch PIL-3, spring-pressed. to open position, may be provided to establish connection through leads I00 and |02 from lead 29 to lead 64 so that while the motor is in operation at high speed the solenoid 43 may be energized to apply the brake and open the circuit of the motor without waiting for the operation of the timing device T--I. The switch PB-Z, it will be noted, controls the circuits of both the low speed and high speed windings of the motor so that when the switch PB-2 is operated to energize the low speed winding of the motor the operation of the switch PB-I will not energize the high speed winding. It will also be noted that upon release of the switch PB--2 the spring will return it to its normal position, interrupting the circuit of the low speed winding of the motor and completing the circuit to lead 29 so that the brake may be applied by operation of the switch F13- 3.Y

In the operation of the device the motor will be started by closing the switch PB-I, solenoid 36 of which thereupon becomes energized and holds manipulation of the lever I8 to load the basket g with the material to be treated. Upon completion of the loading of the basket and the closing of the gate I6 the switch SW-2 is closed completing the circuits for the timing devices T-I and T-2 causing the motors of these devices to start operating. At a predetermined time after the initiation of the operation of the motor 52 of timing means T-2 the contacts 56a are closed,

energizing the solenoid 12 to supply the liquid for washing the material in the basket, the time elapsing before the contacts 56n are closed being determined to provide suiilcient time to centrifuge the mother liquor from the material -being treated. The solenoid 12 is maintained energized and washing liquid is supplied to the basket until the contacts 56b are opened whereupon the solenoid 12 is de-energized and the supply of liquid to the basket is cut off. The timing means T-I is meanwhile operating and upon completion of the ywashing and centrifuging of the wash liquid from the basket the contacts 56 are closed energizing the solenoid 43 and supplying air to the cylinders 48 and 4I, applying the brake shoe I2 to the brake drum I0 and operating the switch SW-i to interrupt the circuit of the high speed winding of the motor, decelerating the centrifugal. Upon opening of the motor circuit, solenoid 36 is deenergized and switch` PB-I allowed to open. Where the material Ais removed from the basket by hand or the bottom of the basket is dropped in order to discharge the'dry material therefrom the braking operation will be allowed IAC to continue until the basket has Abeen stopped. Thereupon the lever i8 is operated sufficiently to rest the lever on ythe shoulder |04 of the bracket lil which holds the lever raised suiciently to open theswitch SW--2 while the basket is being Aunloaded but does not raise the gate I6 sufli-A ciently to permit discharge from the filling spout M to the basket. Where an unloading device is used and it is desired to operate the motor at suitable low speed in order to operate the unloading device the lever i8 can be operated when the speed vof the motor and basket is sufciently decelerated so as to open the switch SW-2 and cie-energize solenoid 43 to release the brake and the switch PB-Z is operated to close the circuit of the low speed winding, the switch PB--2 being` retained closed manually during the unloading operation. Upon removal of the unloading means the switch PB-I is again closed to operate the basket at high speed andthe lever loperated to open the gate to load the basket. `Upon completion of the loading of the basket the gate I6 is closed causing the switch SW--Z to be closed and initiating the operation of the timing means T--l and T-2 for another cycle of operations.

While a brake shoe l2 and a brakev drum I ll have been shown as the means for decelerating the centrifugal it is to be understood that such showing is for the purpose of illustration only as the piston 50 may be used to operate or control any of the usual braking or decelerating means or systems such as regenerative braking or the reversal of the current to the .motor where the motors are equipped for deceleration by such means and that by the expression means for decelerating as used in this application is meant all the usual braking or decelerating means or systems.

What is claimed is:

' 1. The combination with a4 centrifugal machine having a basket, vof manually controlled gate means for loading the basket, means for decelerating said machine, automatic timing means for causing operation of said decelerating means and means for starting said timing means operated by the movement of said gate means to closed position.

2. The combination with a centrifugal ma` chine having a basket, of means for loading the basket, automatic means for eiecting Washing of the basket contents for a predetermined period and fordecelerating said machine and means operated by the movement of said basket loading means to closed position for starting operation of said automatic means at predetermined periods after the stopping of the loading of the basket by said loading means.

3. The combination with a centrifugal machine having a basket, of means for loading the basket, automatic means for effecting washing of the basket contents for a predetermined period and means operated by the movement of said basket loading means to closed position for starting operation of said automatic means at a predetermined time after the stopping of the loading of the basket by said loading means.

4. The combination with a centrifugal machine having a basket, of gate means for loading the basket, automatic means for eiecting washing of the basket contents and means operated by the operation of said gate means to closed position for starting operation of said Washing means.

5; The combination with a centrifugal machine having a basket, of gate means for loading the basket, means for washing the basket contents, means for decelerating said machine, automatic Itiming means for controlling the Washing and de'- celerating means and means operated by the operation of said gate means to closed position controlling operation of said timing meansl 6. The combination with a centrifugal machine having a basket arranged for electric motor operation at high and low speeds, means for loading the basket, means for washing the basket contents and for decelerating the machine from high speed, said decelerating means opening the motor circuit for high speed operation, timing means controlling said Washing and decelerating means, means operated by the closing of said basket loading means for startingvsaid timing means and means for completing the circuit for low speed operation of the motor.

7. The combination with a centrifugal machine having a basket, of manually controlled gate means for loading the basket, means for decelerating said `machine and automatic timing means placed in operation by the movement of said gate means to closed position and causing operation of said decelerating means upon said gate means being held closed for a predetermined period after being closed.

8. The combination with a centrifugal machine having a basket, of manually controlled gate means for loading the basket, means washing the basket contents pand automatic timing means placed in operation by the movement of said gate means to closed position and causing operation of. said washing means upon said gate means being `held closed for a predeterminel period after beingV 

